1. Field of the Invention
This invention relates to the process of polyene hydrocyanation using promoters and, in particular, to hydrocyanation of dienes by hydrogen cyanide, a nickel catalyst, and a promotionally effective amount of an aryl alcohol.
2. Summary of the Background
It is known that the addition of hydrogen cyanide to double bonds adjacent to an activating group, such as a nitrile or carbonyl group, proceeds with relative ease. The addition of hydrogen cyanide to unactivated double bonds, however, proceeds only with difficulty, if at all, and normally requires the use of high pressures of about 1000 psi (7 MPa) or more and high temperatures in the range of 200.degree. to 400.degree. C.
Arthur, et al., U.S. Pat. No. 2,571,099, disclose an improved hydrocyanation process that involves the use of nickel carbonyl, Ni(CO).sub.4, with or without the addition of a tertiary aryl phosphine or arsine. This process produces a relatively high percentage of undesirable polymeric products when applied to monoene starting materials and a relatively poor yield in all cases. Furthermore, this process is not satisfactory for the production of adiponitrile (ADN) from 3 or 4-pentenenitrile (3PN or 4PN).
Drinkard, et al., U.S. Pat. No. 3,496,215, disclose a process for hydrocyanating olefinically unsaturated organic compounds with zerovalent nickel phosphite catalysts of the general formula, Ni(PXYZ).sub.4, wherein X is OR and Y and Z are selected from the class consisting of OR and R, wherein R is selected from the class consisting of alkyl and aryl groups having up to 18 carbon atoms.
Drinkard, et al., U.S. Pat. No. 3,496,217, disclose an improvement in monoene hydrocyanation using a nickel catalyst and a metal cation promoter selected from the class consisting of zinc, cadmium, beryllium aluminum, gallium, indium, silver, titanium, zirconium, hafnium, germanium, tin, vanadium, niobium, scandium, chromium, molybdenum, tungsten, manganese, rhenium, palladium, thorium, erbium, iron, and cobalt.
Chia, et al., U.S. Pat. No. 3,766,237, disclose an improved process for the hydrocyanation of selected unsaturated organic compounds utilizing a nickel complex catalyst, preferably of the general structure ##STR1## wherein A.sup.1, A.sup.2, A.sup.3, and A.sup.4 are neutral ligands that may be the same or different and are selected from the class consisting of M(XYZ) wherein M is selected from the class consisting of P, As, and Sb, and wherein X, Y, and Z may be the same or different and are selected from the class consisting of R and OR, and wherein R is selected from the class consisting of alkyl and aryl groups having up to 18 carbon atoms, in the presence of an excess of a triaryl phosphite having the formula, P(OAr).sub.3, wherein Ar is selected from the class of aryl groups of up to 18 carbon atoms. Use of a promoter is not necessary in this process; however boron compounds or cationic forms of a metal selected from the class consisting of zinc, cadmium, beryllium, aluminum, gallium, indium, thallium, titanium, zirconium, hafnium, erbium, germanium, tin, vanadium, niobium, scandium, chromium, molybdenum, tungsten, manganese, rhenium, palladium, thorium, iron, and cobalt can be used.
Shook, et al., U.S. Pat. No. 3,903,120, disclose an improved process or the synthesis of zerovalent complexes of nickel of the types, Ni(MZ.sub.3).sub.4 and Ni(MZ.sub.3).sub.2 A, with a ligand such as MZ.sub.3 wherein M is P, As, or Sb, Z is R or OR, and R is an alkyl or aryl group having up to 18 carbon atoms and the R's of a given ligand may be the same or different, and at least one Z is OR, and A is a monoene having 2 to 20 carbon atoms.
Shook, U.S. Pat. No. 4,082,811, discloses a process for the recovery of catalyst components from a catalyst residue obtained from the hydrocyanation of olefins using a catalyst comprising zerovalent nickel complex promoted with a triarylborane and comprising nickel cyanide, triarylborane, and complexes of the foregoing. Additionally, a recent description of the hydrocyanation process can be found therein.
Taylor, et al., U.S. Pat. No. 3,778,462, and Wu, et al., U.S. Pat. No. 4,151,194, disclose a process for hydrocyanations of monoenes wherein the hydrocyanation reaction is carried out in the presence of a zerovalent nickel catalyst, a promoting amount of a cation of a metal constituting the required Lewis acid, and using a solvent that is an aryl compound containing from 6 to 20 carbon atoms per molecule and containing at least one hydroxyl group directly connected to a ring carbon atom that includes phenol and cresols.
Taylor, et al., J. Cat. 26, 254-260 (1972), report monoene hydrocyanations run in cresol solvents in the necessary presence of a Lewis acid and that, in these Lewis acid-promoted reactions, cresol solvents show increased rates over reactions run in toluene or acetonitrile solvents.
Wu, et al., Symposium on Homogeneous Catalysis, Am. Chem. Soc. 372-381 (1980), report that, in contrast to monoene hydrocyanation, phenol and cresol solvents do not lead to rate enhancement in diene hydrocyanation.
A general summary of nickel-catalyzed olefin hydrocyanation is found in Tolman, et al., Adv. Cat. 33, 1-46 (1985).
None of these references discloses or suggests the instant process of polyene hydrocyanation using a promotionally effective amount of any acid with a pK.sub.a above about 2 and below about 14, preferably from about 6 to about 12, in the presence or absence of a solvent.